Concrete breaking machine



March 1 6, 1954 w v co N -r 2,672,331

CONCRETE BREAKING MACHINE Filed June 17. 1948 Tic. .L.

5 Sheets-Sheet 1 INVENTOR 75 Wm new 14 tam/5T1 BY L ymhm, 9M&W,

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5 Sheets-Sheet 3 Filed June 17, 1948 i lllllll HHIIIIL 9 8 w I W m m i M1 W h. 0" l o @15 m w 9 5 7. I w "w m INVENTOR ATTORNEYS March 16, 1954 Filed June 17, 1948 T1213- I E W; V. CORNETT CONCRETE BREAKING MACHINE 5 Sheets-Sheet 4 TILEI.5.

INVENTOR 14 41 TEE/4 COF/YETT BY 16m M, 1 m 1, a

ATTORNEYS 5 Sheets-Sheet 5.

Filed June 17, 1948 INVENTOR 14 4475}? 1 Com/arr hm, M 813% ATTORNEYS Patented Mar. 16, 1954 UNITED STATES ATENT OFFICE 2,672,331 CONCRETE BREAKING MACHINE Walter V. Cornett, Los Angeles, Calif. Application June 17, 1948, Serial No. 33,603

6 Claims. 1

The present invention pertains to improvements in concrete breaking machines.

An object of the invention is to provide a machine of the above nature including a supporting frame and a hammer mechanism providing improved mounting means for the hammer mechanism and for adjusting the vertical position of the latter.

Other objects and advantages of the invention will appear in the course of the following description in connection with the accompanying drawings, in which Figure 1 is a rear elevation of a preferred form of the invention;

Figure 2 is a side elevation of the same;

Figure 3 is a downwardly directed sectional view in the plane 3-3, Figure 2;

Figure 4 is a detail front elevation of the hammer operating structure;

Figure 5 is a vertical sectional view of the 3 same;

Figure 6 is a fragmental detail view of the vertical locating latch structure;

Figure 7 is a vertical sectional view of the same on the lines 1-1, Figure 6;

Figure 8 is a side elevation of the device showing an alternative form of elevating and cushioning means; and

Figure 9 is a diagram illustrating the operation of the machine in a circular path about one wheel as a pivot.

Referring to Figures 1, 2 and 3, the numeral [0 denotes a frame of generally triangular shape, preferably of welded steel construction. A front wheel II is vertically swivelled by a pivot I2 in a support I3 secured to the front corner or apex of the frame It. A drag bar M is attached to the upper end of the pivot i2 for coupling to a truck or hauling means. The bar I4 is horizontally hinged at so that it may be swung upward to vertical position when desired, and a laterally extending handle [6 is secured to the bar to permit the latter to be operated as a steering post. A latch l7, Figures 2 and 3, is provided to hold the bar M in vertical position. The wheel H carries a pneumatic tire 18.

Two parallel rear wheels I 9 and are rotatably mounted on an axle 2| secured to the rear of the frame [0 by means of legs Ma and are also provided with pneumatic tires 22 and 23 respectively. The wheel !9 has attached thereto a sprocket 24 connected by a chain 25 to the driving sprocket 26 of a reversible compressed air motor 2'! secured to the underside of the frame I0. Two transverse shafts 28 and 29, rockably secured to the frame I0, have attached to their outer ends curved brake shoes 30 and ti adapted to engage the upper peripheries of the tires 22 and 23 respectively. Arms 32 and 33 on the rocker shafts 28 and 2% are connected by toggle links 34 and 35 with pivots 36 and 3'! in the rearwardly extending arms 38 and 39 of bell-cranks 49 and 4!, the vertically directed arms 42 and 43 of the bell-cranks i0 and ll comprising handles for applying the brakes. When the handles 42 and 43 are thrown rearwardly to apply the brakes, the pivots 36 and 3"! may be thrown below center against the resilient resistance of the tires 22 and 23, the resilient pressure of the tires thereafter holding the mechanism in toggle locked position with the brakes in engagement. It will be noted that the two brake mechanisms are independent of each other, allowing either bra-ke to be operated without the other as desired. Light retracting springs 44, attached to the toggle pivots 36 and 31, serve to normally hold the brakes in disengaged position.

A pair of vertical channel members 45 and 46, Figures 1 and 2, secured to the frame It, form guide-ways for a cross-head member 41. A second pair of channel members 48 and 49 similarly form parallel guide-ways for a second cross-head member 50, Figure 1. A compressed-air cylinder 5|, shown in detail in Figures 4 and 5, has a lower head 52 provided with opposite lateral extensions 53 and 54 J'ournalled or trunnioned in the members 47 and respec-- tively.

Vertical supporting and positioning rods 55 and 56, secured to the upper sides of cross-heads 41 and 50, are slidably mounted in flanged guide members 51 and 58 disposed on synthetic rubber cushions 57a; supported on plates 59 and 60 comprising the upper bracing members of the channel cross-head guides as shown in detail in Figure '7. The flanged guides El and 58 are vertically movable on bolts 6|, and are normally held down against the cushions 51a by compression springs 62.

The front sides of the rods 55 and 56 are provided with series of parallel slots or notches 63 adapted to receive latches St and 65, pivotally secured to lateral extensions of the flanged guide members 57 and 58. The latches 64 and 65 normally rest in any chosen pair of notches 63, thus supporting the cross-heads and air cylinder at the desired height. Knuckle links 65 connect the latches 64 and 65 to lever arms 61 and 68 on a transverse shaft 69. A downwardly directed handle 10, Figures 1 and 2, when moved forwardly, rocks the shaft 69 and withdraws the latches 64 and 65 from the notches 68 when it is desired to change the vertical location of the air cylinder as hereinafter set forth.

It will be noted that the guide members iii and 58 are slotted to receive the latches 64, and that when the latter rest in the rod notches 63 they look the rods against motion either upward or downward-inthe guide members.

The vertical cliannel'g uides 45, ,48, 48 andzlla are braced on the frame iii by forward and rear members ll and 12.

Referring to Figure 5, the numeral 13 denotes a pneumatic piston fitting in the cylinder fi 'l and secured on the upper end of a pistonrodflil .slidable through the lower head 52 via a gland it. The lower end of the rod 14 carries atmassive hammer 16 adapted to receive and hold abreaker or cutting tool 11 of any desired form dependent on.the.type of work. A" vertical guide rod 18 is? fastened in" a rearward extension is -of-' the lowerrcylinder head -2,,anda lu-g; tll'on-the'ham' mar 16, slid'ab'le onthe guide-- rod IS-j prevents the" hammer from-turning 'dllfingf operation:

A laminated semi-elliptic spring 81 is secured to an angle plate 8-2? bolted to" theend of the: axle extension 535 The'spring bears-"against ar vertical angle-guide 83" welded or otherwise* secured to the=-channel-member-dfit The-spring 8F normally holds thehammer" and operatnig assembly vertical position; but" is yieldabl'e to" allow limited forward' or rearward swing of the assembly in the cross-heads lland i 51'! when such shifting facilitates?- certain types of worir.

A iour=way valve*84(Figs. l and 2)- provided with an exhaustduct B'J -and an inlet fitting for attachment of' a flexiblea-ir-supply hose, is connected via flexible hoses- 81- and 88- to the lower andupperendsof the cylinder 51-; Ahan'-- dle 89 on the valve 84- is manually operable to admit compressed air above-or below the piston 13 for controlling the up and down action" of thahammer'and'toollsecond valve 90;, havin an air supply connection. 91* and connecting-tubes 92 and 93 to: tlie reversihleair-motoril, is al'sc'ma'nuall'y op' arable by a handle B l to control theair motor: Adopt-pedal contro1 9 2a; Figure 3; mayal'so -b'e provided for the'v-al've- 901 The numeral 95'; Figures; a'an'd 3: designates at small oil reservoir from which oil may be fed through wtub'e 95 to thecylinder 51 A suitable seat 91 is secured to the framedfl" in position" lac-place the" previously described'cont'rollevers and st'eering means within convenient reach of the operator;

In operation; the machine is connected to asuitable= source of compressed air" and maneuvered into position to lineup the hammer- 16's andtool FF above the point" at which the work= i'stO-bestartrad'. The height 'setting of 'the cylin der- 5i i is adjusted to I bring the effective stroke of! tlieL-hammerto the desired depth of cutting position, The vertica1 adjustment of the cyl'-- inder "is accomplished i in 1 the following manner:

If it is: desired to 1 lower the cylinder 5| the control valve was operated to allow 'thahammer 16* to sink until the" tool- 71 rests against-the: ground or other supportingsurface sucheas-con crete. The lever fllis operated to :withdi'awsthe latches. 6'4: and; 65'! from thenotches 631 the supporting rods 55 and 565 Air-is them-bled into the lower: end 0f: the cylinderaand released from the upperend; permitting the entire cylinder assembiy-twmove' downward until'the desired' po sition is reached, whereupon the latches 64 and are returned into engagement with the corresponding pair of notches 63 to lock the assembly in place. Similarly, when it is desired to raise the cylinder 5 I the hammer or tool is placed against the ground or concrete surface, the latches 154 and 65 are released, and compressed air is admitted to the cylinder above the piston 13. As. thee-latter is. held stationary, by the. supporting ,surf'ace;the air pressuresmoveszzthe cylinder assembly upward until the required position is reached, the latches then being re-engaged with notches B3 to lock the assembly as before.

From thedoregoing it will be seen that the preferredembodiment of the invention as described provides power elevation and adjustment of the assemblyg'tentirely by action of the operating piston and cylinder themselves, promoting extreme simplicity and economy by elimination of any auxiliary elevating devices.

The long range of adj ustment of-"the cylinder height permits the ha-mmer T6 and tool W th-*- be= worked atdepths= well" belowthe level of 'the supporting surface; for eXampI'e indeep cuts=or trenches;

iivliilethe device has been described" as di rect'ed principally tothe breakingof concrete and the like, it is obviously adapted to perform ing variousother related functions -sucli"astampingback filldn trenches; etc;

In breakingconcrete; cutting, etc-L; theoperaton controls the strokes of the hammer lt' by means of thefour-way valve; moving-- the" device by means of the air-motor 2! and steering by thei front wheel H to follow-the line of work; A rincipal feature of "the machine is the-substantially uniform distribution'of theweightzorr-thea three *wlieel's' and the location of the line ofi'impact within the frame and-'=c-l'oselyadjacent the" center of'the triangle formed" by the points of contact of the three tires with the ground. balanced construction causes an even-cushioning chest to be provided-by the three tires; steadying the macliine against rocling or surging, and preventing any tendency to cra'wl or*walk out of proper position;

Sizpplment'ng the cushioning effect/moi the: pneumatic tires, further resilient shock absorp tionis' provided by upward" and downward movementof the plates 5T; and 58 -between the springs 62 and the rubber cushions 51a, Figure-7f Tlie=central location. of the' hammer mechanism; iii-addition to its-inherent steadiness; hast the'further advantage of eliminating the ne cessity-fcrthe heavy counter balancing and an choring required with 1 over-hung hammer 'struc titres: Thus, since all the dead WGlgI'lVOf thB device is eifi'c-iently and evenl-y available fdr backa in up the hammer blows, the invention provides a machine-of'high impact capacity-with comparatively small size and weight. 'I'hese lat' tar-qualities; together with the easyone-man: maneuverability provided by' the steering; pro'-= polling and braking: means described, render the: device especially applicable to" work crowded situations wherein lar'ger machines could beoperated only with great difficulty if at 2:111 Forexample, themachine can readily be run down a: sidewalk totcut'openlngs for-the:-

5- installation of subsstructures.--

Another: example of i work'- to which the d'e-'-- vice is especially adapted the quiclteuttingof small openings in paved streets; Circulan open ings of approximately four' foot diameter are aacommon: requirement, andfin. preferred form:

the present device may be properly proportioned to out such openings with ease and rapidity by the method illustrated diagrammatically in Figure 9.

To carry out the method, the machine is run into position with the tire 23 of the rear wheel 20 resting at the center of the desired cutting path, and the wheel 20 is locked by means of the brake-shoe 3!. As previously described. The front wheel ll is swung to tangential position and the rear wheel I9 is revolved by the airmotor 21. This causes the entire machine to pivot about the locked rear wheel 20 as a center, and operation of the hammer I6 at the same time causes a circular cut to be made on the path 98 as desired, the radius of the path being the distance 99 between the vertical axis of the hammer mechanism and the center of the wheel 20. Since, as noted, circular cuts of about four feet diameter are a very common requirement, the machine may advantageously be proportioned to out such holes by the locked wheel method described, but it will be obvious that the same machine may readily be used to cut larger or smaller openings of circular or any other desired shape simply by steering it in the proper path. The extreme mobility of the entire machine eliminates any necessity for any traversing or shifting means between the frame and the hammer mechanism, such as are required in prior devices with overhung hammers and the like.

Figure 8 illustrates an alternative form of elevating and cushioning mechanism for the air cylinder and hammer assembly.

Referring to Figure 8, each cross-head or trunnion member I00 is attached to the upper end of the piston rod IOI of a hydraulic cylinder I02, individual cylinders and rods being provided for the two cross-heads. A small hydraulic pump I03 is adapted to receive hydraulic fluid from a tank I04 and force the fluid into the cylinders I 0| below pistons I05. The upper ends of the cylinders I M are connected via tubes I06 with a small valve I01 adapted to supply compressed air or release the air above the pistons I05.

Elevation and lowering of the hammer and pneumatic cylinder assembly is accomplished by pumping hydraulic fluid into or releasing the fluid from the lower end of the cylinder I02. When the hammer is to be operated, compressed air is admitted above the pistons I02 to form cushions against upward motion. Similarly the hydraulic fluid supplies a degree of resilience below the pistons I02. Thus the entire hammer operating assembly is supported between hydraulic and pneumatic cushions which supplement the cushioning efiect of the tires I8, 22 and 23. While the invention has been described in preferred form it is not limited to the exact structures illustrated, as various changes and modifications may be made without departing from the scope of the appended claims.

What is claimed is: I

1. In a device of the character'described, in combination, a frame, vertical guides attached to said frame, a pair of cross-head members slidably disposed in said guides, a pneumatic cyl-' inder having an upper and a lower head, lateral cylindrical extensions on said lower head trunnioned in said cross-head members, resilient means to normally hold the axis of said cylinder parallel to said guides, a piston in said cylinder, a piston rod secured to said piston and slidably extending through said lower head, a hammer secured to the lower end of said piston rod, and adjustable means to support said cross-heads substantially at predetermined heights in said guides.

2. A device as claimed in claim 1 including an auxiliary vertical guiding member, and wherein said resilient means comprises a leaf spring centrally secured to one of said cross-head members, the terminal face portions of said spring engaging said auxiliary guide member.

3. A device as claimed in claim 1 wherein said supporting and locking means includes upper guide members attached to the said first-mentioned guides, vertical rods slidably mounted in said upper guide members and having their lower ends attached to said cross-head members, said rods having spaced parallel notches therein, and manually withdrawable latches attached to said upper guide members and normally engaging parallel notches in said rods.

4. A device as claimed in claim 1 wherein said supporting means includes second guide members attached in vertically cushioned relationship to said first mentioned guides, vertical rods slidably mounted in said second guide members, said rods having spaced parallel horizontal notches therein, latches pivoted to said second guide members and normally engaging parallel notches in said rods, and means operatively connected to said latches and including a single manually operable lever to simultaneously disengage said latches from said notches.

5. A device as claimed in claim 1 wherein said supporting means includes hydraulic cylinders below said cross-head members, said hydraulic cylinders having pistons therein and vertical rods attached to said cross-head members, and pumping means to force hydraulic fluid into said hydraulic cylinders below said hydraulic piston whereby said cross-heads and said pneumatic cylinder may be elevated and vertically supported in said guide members.

6. A device as claimed in claim 1 wherein said supporting means includes hydraulic cylinders below said cross-head members, said hydraulic cylinders having pistons therein and vertical rods attached to said cross-head members, pumping means to force hydraulic fluid into said hydraulic cylinders below said hydraulic pistons, and means including a control valve and conduits to admit compressed air to said hydraulic cylinders above said hydraulic pistons.

WALTER V. CORNETT.

References Cited in the file of this patent Mosena et a1 July 8, 1947 

